It is known to use large corridor type furnaces for preheating billets of steel or other metals prior to some industrial operation such as rolling or hot forming. Such furnaces typically utilize walking-beam carriers to cause a group of billets to progress through the furnace in intermittent or stepwise fashion. In this arrangement the billets are placed in spaced-apart parallel fashion with their axes transversely of the furnace and the walking-beam mechanism lies generally in the center of the furnace so as to pick up a group of billets and move them forward by six or eight inches depending upon the throw length of the walking-beam mechanism.
The walking-beam mechanism may, for example, comprise a long channel shaped steel body which is covered or lined with refractory tiles or blocks. The blocks themselves are preferably configured in such a fashion as to provide stable support locations or seats for the billets both in the rest positions at opposite ends of the throw and on the walking-beam carrier itself so that the billets do not move around or become misaligned during the throw.
One known technique for providing the aforementioned support locations or seats involves lining the walking-beam carrier surface as well as laterally adjacent support surfaces with refractory blocks of staggered height, the shorter blocks forming rectangular troughs or recesses into which the billets fall at opposite ends of the walking-beam carrier throw. Another known arrangement involves development such as by casting of liner blocks having a sawtooth top surface configuration to provide the support locations or seats. In one known installation the channel shaped carrier is notched along the side surfaces to conform to the sawtooth configuration of the refractory blocks.
In all of the known installations, significant problems are encountered in maintaining the proper spacing between the support locations or seats so that in all cases they are spaced apart by the throw length of the walking-beam mechanism. In addition problems are encountered in installation and later use where the blocks are very small; i.e., a large number of blocks requires a great deal of mortar work in installation and the presence of a large number of mortar joints not only contributes to the aforementioned dimensional and spacing problems but also to maintenance.